Nothing too exciting here. This seems to be a minor update to Apple’s signature music software. Where version 11.1.2 brought Mavericks compatibility, support for Arabic and Hebrew, and moved all your digital books into the new iBooks app, this update brings the following:

Resolves an issue where the equalizer may not
work as expected and improves performance when switching views in
large iTunes libraries.

This update also
includes additional minor bug fixes.

Improves
performance and stability.

You can get the update by going to Apple’s downloads page, or it should be ready and waiting for you the next time you launch the App Store app.